The Indiana State Board of Animal Health said Monday that laboratory testing of a commercial duck flock in Elkhart County has come back as presumptively positive for the virus.

Laboratory testing of a second commercial duck flock in Elkhart County came back as presumptively positive for the virus, the Indiana State Board of Animal Health said.

Laboratory testing of a fourth commercial turkey flock in Dubois County has come back as presumptively positive for the virus, the Indiana State Board of Animal Health said. The samples are being verified at the U.S. Department of Agriculture’s National Veterinary Services Laboratory in Iowa.

Avian influenza has been detected in a fourth commercial poultry flock in southern Indiana, state officials said Saturday.